It is known that filamentous fungi, namely molds, have various functions, which have been beneficially utilized in various fields.
For example, some filamentous fungi have a function to control plant diseases caused by pathogenic filamentous fungi. Pathogenic filamentous fungi may cause diseases, such as damping off, root rot, leaf rot, and wilt in agricultural products including many vegetables, such as cabbage, cucumber, tomato, eggplant and rape leaf, and rice; flowers; trees; turfs, and others. Well-known pathogenic fungi include those belonging to the genus Rhizoctonia, the genus Fusarium, the genus Pytium, the genus Trichoderma, and the genus Sclerotium. Although chemicals, so-called agricultural chemicals, are generally applied in order to control such plant diseases caused by filamentous fungi, methods of biological control using microorganisms (so called microbial pesticides), which are believed to be safer to the environment, have been proposed and some have been used practically.
Known examples thereof include a technique to utilize bacteria belonging to the genus Pseudomonas for controlling a plant disease caused by a filamentous fungus (see e.g. JP 11-187866 A), a technique to utilize a nonpathogenic filamentous fungus belonging to the genus Trichoderma or the genus Mucor (e.g. see JP 10-150978 A), and a technique to utilize a nonpathogenic filamentous fungus belonging to the genus Fusarium (see e.g. WO 97/31521).
Meanwhile, a certain filamentous fungus having a control function against such a pathogenic filamentous fungus has been discovered and a technique to utilize it as a non-residual plant disease control agent having a stable disease control activity has been developed (see e.g. WO 2006/085567). In case such a plant disease control agent is carried by compost, not only a stable plant disease control activity can be obtained, but also a soil improvement effect can be expected.
Further, a decomposing material for chlorinated organic compounds such as a dioxin is known which is obtained by culturing basidiomycetous white-rot fungi, which is another filamentous fungus having a function, on a microbial carrier with a C/N ratio of 30 to 35 (see e.g. JP 2003-334061 A). Further a filamentous fungus belonging to the genus Trichoderma is known to have a significant decomposing activity on petroleum related materials, especially on a crude oil and an aromatic hydrocarbon fraction which is a persistent component of the crude oil (see e.g. JP 06-319529 A).
However, even if such a filamentous fungus having a function is carried in compost having a soil improvement activity, it takes long time before the intended filamentous fungus stabilizes in the carrier compost. Furthermore, since bacteria also participate in composting, simple addition of a specific filamentous fungus during a composting process may not lead to efficient proliferation, or successful development, of the intended function.